The rechargeable lithium batteries currently used contain graphite as anode material. Graphite acts as a lithium insertion material and according to the equationLi+6C→LiC6 it has a theoretical capacity of 372 mAh/g with a potential of approx. 0.2 V vs Li/Li+. The much higher storage capacity of lithium metal (3860 mAh/g) cannot be used in batteries suitable for practice, since batteries of this type are not safe or cycle-stable. In cycling, the lithium metal is in part not deposited in a planar manner, but in the form of growths (dendrites). These growths can be detached from the metal anode, whereby the electrochemical cell loses capacity accordingly. The consequences are even more serious if needle-shaped dendrites penetrate the separator. The battery cell can thereby be short-circuited with often catastrophic consequences: thermal run away, often accompanied by fires.
There have therefore been efforts to use lithium alloys instead of pure lithium metal as anode material. However, lithium alloys exhibit extremely strong volume fluctuations with lithium intercalation and deintercalation (in part several 100%, e.g., Li9Al4: 238%). Alloy anodes, with the exception of tin-graphite composites, have therefore not become established on the market. However, tin is a rare and expensive element, which has prevented the wide use of materials containing tin.
Tarascon and Aymard proposed an electrochemical cell in which lithium hydride is used as a negative electrode (anode) (EP 2026390A2):MHx+LixLiH+M  (1)where M=La, Mg, Ni, Na, Ti
However, the Mg-based system described in detail in the above-mentioned patent specification has a marked hysteresis and it has not hitherto been possible to demonstrate its functionality in a real lithium battery.
An anode material is sought, which avoids the disadvantages of the prior art, i.e. has                A high capacity (>>372 mAh/g)        And at the same time a good reversibility        And does not contain any expensive or toxic constituents.        